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firing: dumping water

updated fri 6 apr 01


Tom Buck on thu 5 apr 01

Jane Powers:
Dr Vandiver's slide showed water on the top of a kiln; and she
said it was there to be let into the very hot kiln when top cone is
reached. In China, a wood-fired kiln would usually be at Cone 10 (approx
1300 C, 2400 F) when the water is sent into the top of the kiln. The ware
and the kiln walls provide enough iron oxide to act as catalyst for the
"water-gas reaction"

H2O + C = H2 + CO

(the C comes from the burnt wood; the hot carbon particles would still be
present while the kiln is being stoked and these are both strong reducing
gases to make copper reds, etc. Thus, a simple way to conduct reduction
without using today's technology.
and FYI, this water-gas effect occurs in our gas-fired kilns
today, especially on a rainy day.
til later. Peace. Tom B.

Tom Buck ) tel: 905-389-2339
(westend Lake Ontario, province of Ontario, Canada).
mailing address: 373 East 43rd Street,
Hamilton ON L8T 3E1 Canada